Office has been a big part of my computing life. Its really well written software and it isn't hard to see how Microsoft made a fortune on it. I'd say my usage was typical - Outlook was always open, and I made frequent use of Word and occasional use of PowerPoint and Excel. I've also used OneNote quite a bit since its addition. I wrote the Foundations of Programming in Word 2007, which I think is a great app - ribbons are good, and Calibri is a wonderful font. I use Word the way its meant to be used - my style window is opened at all times, and even a complex document like Foundations of Programming is clean and well managed.
A few months ago I started using gmail seriously and became instantly hooked. That gmail is better, in almost all respects, to Outlook is a certainly a testament to the web and Google, and possibly to Microsoft's lack of innovation. Searching is faster and more accurate. Archiving is better than deleting. Spam filtering is virtually 100% effective. There is no stupid PST management. Best of all, it turned email into a highly effective conversation medium.
As a web programmer, I'm ashamed to say this, but it wasn't until my Gmail experience (in 2010!) that I truly believed that a web application could thoroughly beat out a first class desktop application. Sure, I knew that web apps could have certain specific advantages, but to beat a desktop app on things like performance and usability was a real shock for me.
With that realization behind me, I started to question my belief that other parts of Office were so special. A large chunk of my Word usage was replaced with Wikis. Also, having a thousands fonts, styles and fancy features just doesn't appeal to me anymore. Give me a text editor or maybe Google docs and I'm more than happy to write until I can't write anymore.
PowerPoint? The best presentations have strong presenters and static slides, which for all intents and purposes could be images. As far as I'm concerned, if you are using PowerPoint to even 25% of its potential, your presentation will probably suck. OneNote? I use keepass for my accounts and The Hit List for todos.
There was a point where running the latest copy of Office was pretty cool (geek!), but no more. Those are my parent's tools, not mine. I have no interest in Office 2010 or any Office versions.. Its a very expensive product - in some cases its a really bad product (PowerPoint, Outlook) and in others its a really good one (Word, OneNote) but well beyond anything I or [probably] you need.
(I also want to point out that Office on the Mac is horrible. The more I used my Mac, the more I realized I didn't need Office - because using it was outside the realm of possibility.)